I can't imagine what GOG's disadvantage (or fear?) would be, if it could be made possible to ask from support to remove an unwanted game. People don't want a refund, nor an exchange with an other game of equal price. Just the capability to remove from the library an unwanted game, because we didn't like it and we don't want to have it litter the library with its presence. I'm talking about games bought before there was the refund option. Or is GOG afraid that if we change our minds again and we want that game back, we would demand to be given back for free? No, nothing of the like. It could be stated explicitly that if one wants that game back, then he would have to buy it again.
From my part, I regret having bought Pathologic 1. Unfortunately I bought it first and read about its strangeness and high difficulty later! I haven't tried it, I haven't even downloaded it, not even once!